The present invention relates to an apparatus and method for filling flexible containers in an aseptic environment.
Flexible bags, comprised of a plastic material, such as polyethylene, are well suited as containers for fluid substances, such as milk, water, fruit juices, wine, and chemicals. Typically, a spout is provided, through which the container may be filled and the contents may be dispensed. The containers may be connected in continuous web form and filled by advancing the web of containers seriatim into a filling station, as described in U.S. Pat. No. 4,120,134, issued on Oct. 17, 1978 to William R. Scholle, and assigned to Scholle Corporation. The specification of that patent provides useful information helpful in understanding the context in which the present invention operates, and therefore, that patent is hereby incorporated herein by reference.
The apparatus described in U.S. Pat. No. 4,120,134 includes (a) feed means comprising conveyors for directing the continuous web, formed by the interconnected containers, from a supply carton onto a platform adjacent the filling station; (b) guide members for aligning the filling spout of each container as it moves along the platform; (c) a mechanism for uncapping, filling, and recapping each container at the filling station; and (d) means for releasing the filling spouts after each container is filled. As described in this patent, the containers may be advanced either by a mechanically driven conveyor or an inclined passive conveyor. The passive conveyor utilizes the gravitational force of the filled containers on an inclined unloading conveyor to pull the web of empty interconnected containers behind it.
Where the contents of the containers are consumable, measures must be taken to insure that such contents are free from contamination. If, for example, the containers are filled with high acid foods, it is necessary that the filling be performed under at least sanitary conditions. However, where low acid or neutral pH foods, such as milk, are involved, it is desirable that the filling be performed under aseptic conditions, since this permits such foods to have a longer shelf life than would otherwise be possible.